This morning I got 16 core samples from eight beds just like the one in an earlier post. I put them in a homemade tumbler for 10 min along with about a dozen #3 river rock. The coarse compost on top of the core sample must be structurally week because there is not much sign of it now.
I then put the blocking soil in a microwave for 15 min. to kill all of the weed seeds and any living critters that might do the seedlings harm. This is what the soil looked like after nuking.
I made one test block to see how it would hold together. It is more porous than it looks in the photo also; I am considering using some vermiculite to make it a lighter soil.
As usual, all comments are welcome. John